Initialization in value classes

gistfile1.txt

› cat valueClasses.scala 
class Age(val v: Short) extends AnyVal {
  require(v >= 0 && v < 200, "Must be between 0 and 200")

  def isInfant = v < 2
  def isToddler = v >= 2 && v <= 4
  def isSenior = v >= 50
}

 in ~/Downloads/  
› ./scala-2.10.0-RC5/bin/scalac valueClasses.scala
valueClasses.scala:2: error: this statement is not allowed in value class
  require(v >= 0 && v < 200, "Must be between 0 and 200")
         ^
one error found

 in ~/Downloads/  
›